Problem: $ {3\cdot \left[ \begin{array}{cc} -2 \\ -2 \\ 1 \end{array} \right]=}$
The Strategy To multiply a matrix by a scalar, we multiply each term of the matrix by the scalar. Multiplying each term $ {\begin{aligned}3\cdot \left[\begin{array}{rr} {-2} \\ {-2} \\ {1} \end{array}\right]&=\left[\begin{array}{rr} 3\cdot{-2} \\ 3\cdot{-2} \\ 3\cdot{1} \end{array}\right] \\\\&=\left[\begin{array}{rr} {-6} \\ {-6} \\ {3} \end{array}\right]\end{aligned}}$ Summary $ {3\cdot \left[ \begin{array}{cc} -2 \\ -2 \\ 1 \end{array} \right]=\left[ \begin{array}{cc} -6 \\ -6 \\ 3 \end{array} \right]}$